1. Field of the Invention
This invention relates generally to apparatus for cutting metal parts of varying thickness and shapes from workpieces supported on a cutting table and more particularly to an arrangement for supporting the metal workpieces during cutting. Specifically, the workpieces are supported on a plurality of individual point support members which are individually placed on the planar cutting surface of the cutting table in locations dictated by the size and shape of the parts to be cut from the workpieces.
2. Description of the Prior Art
A cutting table for supporting metal workpieces at a cutting station is disclosed in U.S. Pat. No. 4,162,060, where the metal workpieces to be cut are supported on a plurality of spaced parallel burning bars at the top of a water table. After cutting is completed, the slag and scrap resulting therefrom are transferred from the burning bars into a separate container for disposal. In the arrangement disclosed in this United States patent, the water level is raised to a level above the upper surfaces of the metal workpieces for plasma cutting and in close proximity to the lower surfaces of the workpieces for oxyfuel cutting prior to cutting. The water level is lowered after cutting so that the cut metal parts and the slag and scrap may be removed.
Another cutting table for supporting metal workpieces during cutting is disclosed in U.S. Pat. No. 4,453,702. In this patent, the workpieces to be cut rest on spaced parallel burning bars on a dump frame located at the top of a water table. After cutting is completed, the cut metal parts are removed from the burning bars, and the dump frame is tilted to deposit the slag and scrap onto a conveyor. The conveyor transports the slag and scrap from the metal cutting station to disposal means.
In both of the cutting tables described heretofore, the spaced burning bars are in direct contact with the metal workpieces during cutting, and the torch flame or plasma arc contacts the burning bars during cutting. Over a period of time, the top edge of each burning bar is eroded, and slag deposits build up on the sides of the burning bars necessitating replacement of the burning bars which is both time consuming and expensive. In fact, the burning bars are the most expensive items to replace on a cutting table. In addition, each time the flame or arc passes over a burning bar, the quality of the cut on the bottom surface of the part being cut is adversely effected. The elimination of the burning bars from a cutting table avoids these problems.